Thousands of migratory birds from Siberia and Central Asia may not make it to their winter homes further south as a result of the war in Afghanistan, according to ornithologists in Kazakhstan.

At this time of year, as the northern winter advances, hundreds of thousands of birds fill the skies across Siberia and Central Asia as they make their way to over-wintering sites further south - many via Afghanistan.

The scientists can only wait helplessly for the spring when they can count the numbers of birds who return

Kazakh TV

But Kazakh television said this year birds could fall victim to the war on terrorism.

The television said the fighting could prevent the migrating birds from stopping off in their usual favoured places to rest as they fly over Afghanistan.

It said local ornithologists were worried about many native Kazakh birds.

The wetlands of south-eastern Kazakhstan are home to hundreds of species of migratory birds, including two protected species of pelicans.

Cranes fly thousands of kilometres on their way south

Also at risk are the rare Siberian Cranes, which the International Crane Foundation says are the third rarest of the crane species and arguably the most endangered of all.

Kazakh TV said cranes are extremely sensitive to stress; the air activity and bombing could cause flocks to split up and many could get lost and die.

It said thousands of other birds, including pelicans, flamingos, geese, swans, ducks and cranes, might not make it to their usual winter homes.

Vulnerable

One Kazakh ornithologist said that if this happens and the birds have to over-winter in less favourable conditions, many may not return next spring.

Scientists can only wait and see how many return in the spring

The western and central Siberian Crane (Grus leucogeranus) migrate over 5,000 kilometres to India or Iran and the eastern birds a similar distance from eastern Siberia to China.

The population of pelicans in the wetlands of south-eastern Kazakhstan is considered "vulnerable".

The TV said the scientists could do nothing but wait.

"The saddest thing is that the scientists cannot do anything. They can only wait helplessly for the spring when they can count the numbers of birds who return," it said.

BBC Monitoring, based in Caversham in southern England, selects and translates information from radio, television, press, news agencies and the Internet from 150 countries in more than 70 languages.